I use Hey Siri, works like a champ. Yesterday my 6s Plus sitting on table in same room as I am about 10 feet away. Had my hands full, so I said, "Hey Siri, set timer for ten minutes." The phone comes out of sleep, Siri says timer is set for ten minutes. About 7 minutes later I say, "Hey Siri, how much time left on timer". Phone wakes from sleep, Siri say "two minutes 29 seconds left on timer".
This was like a wow moment, 10 feet from sleeping phone, never touched it, never looked at screen. It worked great. I ask it what temperature is, or what time it is, and it just plane answers. Way cool.